Stress sensitivity origin of extended defects production under coupled irradiation and mechanical loading

The production of extended and mechanically highly consequential defects are investigated under concurrent driving forces of irradiation and stress. By using two -temperature model to account for realistic exchange of energy between the electronic subsystem and the atomic subsystem during cascades, and by controlling mechanical loading in the principal stress space to remove the dependance on a specific coordinate system, we build stress sensitivity maps for various types of irradiated dislocations. Frank loops are discovered to be dictated by volumetric strains, while Shockley partials are sensitive to volume-conserving shear loads. By tracking the microstructural evolutions during coupled irradiation and external loading, and by scrutinizing the temporal-spatial variation of local von Mises stresses near the center-collision region, the underlying mechanisms responsible for those different responses/sensitivities are elucidated. The implications of these findings in regard to a new strategy to control microstructural defects and materials performance are also discussed.